1. Field of the Invention
This invention pertains, in general, to quality control in the manufacture of printed polymeric webs, such as which are used for packaging consumer products such as paper towels and napkins. More specifically, this invention provides an improved method and apparatus for removing defective areas from such a web, and for repairing the web in a near-seamless manner after a defective area has been removed.
2. Description of the Prior Art
Polymeric packaging material for consumer products such as absorbent paper towels is manufactured as a long web of polymeric material that has a repeating pattern printed thereon. The long web is delivered in roll form to a customer, which uses automatic packaging machinery to sever the web at regular intervals corresponding to the repeating pattern in order to wrap each product. In order to prevent misalignment within the automatic wrapping process, it is important that the pattern be spaced at regular intervals throughout the entire length of the web.
Typically, a manufacturer of the printed packaging material will inspect each web carefully for defects before shipping the web to a customer. When a defective area is found, it is cut out of the web, and the two remaining ends are taped or sliced together. The spliced area usually has an unacceptable appearance. It is common practice to mark such areas with brightly colored tape, so that the customer will be alerted to to remove the product that has the spliced area thereon after it is wrapped.
Certainly, customers would prefer to have packaging material that does not include such imperfections. If manufacturers were to discard each roll of material that has an imperfection, however, the cost of packaging material would be made prohibitively high.
It is clear that a need exists in this area of technology for an improved method and apparatus for removing defective areas in a printed polymeric web that is capable of efficiently removing the defective areas, re-registering the two ends, and splicing the web in a manner that is sufficiently strong and invisible to the customer that the customer can package its product without interruption.